1. Field of the Invention
The disclosed and claimed concept relates generally to a dimensional detection system and, more particularly, to a system that employs as few as a single camera and as few as a single laser in performing a dimensional analysis on a workpiece.
2. Background Information
Shipping costs are typically determined based on various measurements of an object being shipped (hereinafter, the “workpiece”). Weight, as is well known, is based upon the mass of a workpiece and can be determined with the use of a scale. Shipping costs can also be affected by the physical dimensions of a workpiece. The expression “dimensional weight” thus relates to a characterization of a workpiece in a fashion that can encompass aspects of both the weight and the physical dimensions of the workpiece or at least an aspect of the more significant of the two. The dimensional weight of a workpiece can be based upon a load as disposed on a pallet. Such a pallet may, and often does, support more than one object. Thus, even if several generally rectangular objects are stacked on a pallet, the resulting workpiece may have a non-rectangular shape.
It is understood that a dimensional weight is a characterization of a workpiece. That is, the workpiece may have an unusual shape or may include several rectangular boxes which are stacked so as to be an unusual shape. While it may be possible to determine the exact volume of such a workpiece, a dimensional weight calculation potentially may “square out” the size of the workpiece. That is, as the workpiece, typically, cannot be made smaller than the greatest length in, or parallel to, any given plane defined by two of three axes, the dimensional weight calculation may take into account the volume of the workpiece as determined by the maximum length along, or parallel to, one or more of the X-axis, the Y-axis, and the Z-axis.
This volume is then divided by a standard unit (166 in.3/lb. (international) or 192 in.3/lb. (domestic)) to achieve a dimensional weight. For example, if a workpiece is measured to be six feet (72 inches) by four feet (48 inches) by three feet (36 inches), the dimensional weight would be calculated as follows: First the volume is calculated as: 72 in.*48 in.*36 in.=124,416 in.3. The volume is then divided by the standard unit, in this example the domestic standard unit: 124,416 in.3÷192 in.3/lb=648 lbs. Thus, the dimensional weight is 648 pounds. The shipping cost would then be determined by using the greater of the dimensional weight or the actual physical weight, as measured by a scale. So, if the workpiece was an iron ingot weighing 2,000 pounds, the actual weight would be used to determine the shipping cost. Alternatively, if the workpiece was a carton of feather pillows weighing 200 pounds, the dimensional weight would be used to determine the shipping cost.
The determination of a dimensional weight is typically performed at a stationary device/station into which a workpiece must be placed. The dimensional weight has typically been determined by a system using time-of-flight data, i.e. providing a wave (either sound or electromagnetic) and measuring the time it takes for the wave to reflect from the workpiece. Such time-of-flight devices typically use a plurality of transducers that must be maintained and kept properly oriented. Such time-of-flight transducers may be expensive. Other systems utilize a plurality of light projection devices, typically lasers, and multiple cameras to create, or emulate, a three-dimensional perspective. Such systems may be disposed in a tunnel or similar construct through which a forklift truck passes while carrying the workpiece. Similar, but smaller systems may be disposed about a conveyor belt that transports workpieces.
At a shipping facility, the dimensional weight of a workpiece may be determined as the workpiece is disposed upon a pallet. A forklift truck or similar device may move the pallet into/onto/through a device structured to determine the dimensional weight. If the device is a station, the pallet is typically driven to the location of the station, after which the dimensional weight is determined, and the pallet and workpiece are moved on for further processing. If the system utilizes a tunnel, the forklift truck drives the workpiece to the location of the tunnel and then drives at a relatively slow pace through the tunnel to ensure the multiple cameras/lasers acquire the necessary data.
Thus, a number of shortcomings are associated with known systems for assessing the dimensions or dimensional weight or both of a workpiece. First, known dimensional weight systems can be expensive to build and maintain. Second, the processing of a workpiece at a shipping facility may be slowed by the required steps of transporting the workpiece to, and positioning the workpiece in, or slowly through, the dimensional weight device.